sravan/system76-coreboot
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

lib: Fix log2_ceil() for 0xffffffff

Browse Source 
Current log2_ceil(x) is defined as log2(x * 2 - 1). When x is larger
than (1 << 31), (x * 2 - 1) won't fit in u32, leading to incorrect
result. Therefore, correct it as (log2(x - 1) + 1). Also add unit tests
for inline functions in lib.h.

BUG=none
TEST=make tests/lib/lib-test
BRANCH=none

Change-Id: If868f793b909a6ad7fc48a7affac15e2c714fa2e
Signed-off-by: Yu-Ping Wu <yupingso@chromium.org>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/59834
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Julius Werner <jwerner@chromium.org>
Reviewed-by: Paul Menzel <paulepanter@mailbox.org>
This commit is contained in:
Yu-Ping Wu
2021-12-02 10:54:32 +08:00
committed by Felix Held
parent 04cf42775c
commit 00c834dc26
3 changed files with 65 additions and 2 deletions
Download Patch File Download Diff File Expand all files Collapse all files

60
tests/lib/lib-test.c Normal file
View File

@@ -0,0 +1,60 @@
/* SPDX-License-Identifier: GPL-2.0-only */
#include <lib.h>
#include <tests/test.h>
void test_popcnt(void **state)
{
assert_int_equal(popcnt(0x0), 0);
assert_int_equal(popcnt(0x10), 1);
assert_int_equal(popcnt(0x10010010), 3);
assert_int_equal(popcnt(0xffffffff), 32);
}
void test_clz(void **state)
{
assert_int_equal(clz(0x0), 32);
assert_int_equal(clz(0xf), 28);
assert_int_equal(clz(0x80000000), 0);
assert_int_equal(clz(0xffffffff), 0);
}
void test_log2(void **state)
{
assert_int_equal(log2(0x0), -1);
assert_int_equal(log2(0x1), 0);
assert_int_equal(log2(0x5), 2);
assert_int_equal(log2(0x80000000), 31);
assert_int_equal(log2(0xffffffff), 31);
}
void test_ffs(void **state)
{
assert_int_equal(__ffs(0x0), -1);
assert_int_equal(__ffs(0x1), 0);
assert_int_equal(__ffs(0x1010), 4);
assert_int_equal(__ffs(0x10000000), 28);
assert_int_equal(__ffs(0xffffffff), 0);
}
void test_log2_ceil(void **state)
{
assert_int_equal(log2_ceil(0x0), -1);
assert_int_equal(log2_ceil(0x1), 0);
assert_int_equal(log2_ceil(0x5), 3);
assert_int_equal(log2_ceil(0x80000000), 31);
assert_int_equal(log2_ceil(0xffffffff), 32);
}
int main(void)
{
const struct CMUnitTest tests[] = {
cmocka_unit_test(test_popcnt),
cmocka_unit_test(test_clz),
cmocka_unit_test(test_log2),
cmocka_unit_test(test_ffs),
cmocka_unit_test(test_log2_ceil),
};
return cb_run_group_tests(tests, NULL, NULL);
}